I have a purple haze plant in 3 rd week of flower I recently flushed the soil with plain water at about 6.8-7.0 I have never had this problem before and its quickly affecting my plant. Here's a leaf picture. Any help is appreciated since I've flushed and the soil isn't dry enough to feed.
It looks like a nute def. check stickies and find "when posting sick plant problems" and fill that out. It will help us to help you.
Here I took a lil extra time fer ya. We need all the info on your grow including: What type of medium; soil or hydro? What brand and type of soil? Indoors or outdoors? What strain? How old are the plants? What type of lights and how many watts? How far from the lights? What is your watering frequency and source of water? What, how much and when was it fed? NPK? What is the medium/runoff pH and PPM if in hydro? What are the temps and humidity in the room? What size pots? Any bugs? Look real close. Any other pertinent info? If any of these questions have already been answered please disregard as I cut and paste this for everyone. If there is leaf discoloration please TAKE PICTURES WITH ALL GROW LIGHTS OFF, ESPECIALLY HPS & LED's. Taking pictures and taking them with lights off, allows us to see what the leaf discoloration looks like.
What type of medium; soil or hydro? Soil What brand and type of soil? Ffof Indoors or outdoors? Indoors What strain? Purple haze g13 seeds How old are the plants?8 weeks 3 flower What type of lights and how many watts? HPS/mg 2000 wts How far from the lights? 2 feet almost What is your watering frequency and source of water? When it drys tap What, how much and when was it fed? NPK? What is the medium/runoff pH and PPM if in hydro? What are the temps and humidity in the room? 78 40% What size pots? 5gallon Any bugs? Look real close. A few gnats which im dealing with from the rain and basement moisture Any other pertinent info? Using the advanced ph perf micro grow bloom with bud blood (which I flushed out and am done using) big bud, bud candy, gh- Cal-mag and hesi super vit. But this didn't happen until after I flushed Ph 6.8.
Your issue is Mn. Get Manganese into your nute regimen and attempt to have a PH run-off of 6.5 and the issue will be stayed... don't expect the browning to go away.